wood/epoxy

[DOCHO]

I'am looking into buying a boat with a hull made out of wood/epoxy.
The boat is a homebuild Bruce Roberts.
Of course I will have the boat surveyed but I want some more info on the (dis)advantages of this method of hull construction. I don't want to build the boat so I do not want info on how to build it but I like some info on longevity, maintenance, repair (in case of an accident) and how an insurance company will look at it. (Are they as apprehensive as with a Ferro cement hull). So the information required after you have build the boat.
Also I would like to know what the situation with osmosis is on these types of construction.
So like you see any info is welcomed. If somebody knows a good website this would be also appreciated.

 

[tangomoon]

Some info ref building here - if you know how it was built - you will understand maintenance needs

http://www.westsystem.com/ss/

Somewhere in here is an article where the Gougeon Brothers go back and assess the building of and longevity of various boats using their Epoxy in the construction

http://www.epoxyworks.com/

If I find some more (in my bookmarks, will let come back.

RM 1050 etc are made ply/epoxy if my recollection serves me right - light, strong are the keywords

 

[boatbuilder]

Go to the library and get Gougeon Bros on boat construction.
It is the bible on wood/epoxy.
Done properly it is a great combination.

 

[Keith 66]

Wood epoxy construction is very strong & light, normally boats like this are sheathed in a thin layer of glass cloth & epoxy then painted with two pack paint, they are relatively easy to repair. If the boat is cedarstrip or cored with western red cedar it will soak up water like blotting paper if the sheathing layer gets damaged. Osmosis is not an issue.

 

[tangomoon]

[ QUOTE ]
Go to the library and get Gougeon Bros on boat construction.
It is the bible on wood/epoxy.
Done properly it is a great combination.

[/ QUOTE ]

People here on the weekends are so much nicer that the rab - sorry, some others lingering about during the week. And knowledagble too

Lovely to see you chaps

 

[DOCHO]

[ QUOTE ]
If the boat is cedarstrip or cored with western red cedar it will soak up water like blotting paper if the sheathing layer gets damaged.

[/ QUOTE ]
So if the boat had an breach in the upper layer there could be a problem even if it was fixed right.
Are there other coring materials than cedar strip or western red cedar. (Probably not balsa for wood/epoxy construction.)

 

[srp]

Wood/epoxy has been around for long enough to be regarded as a proven method of construction. See if you can do a search for the photos showing the construction of the RM as mentioned above, by the forum member rb-stretch - a really good post which he made about a year ago I think. You could probably send him a pm. I believe the RM's are plywood, which I think is the most common material for this construction as far as I know - standing by to be corrected on this!
In your case, you need to assess whether the boat you're considering has been built and maintained to a good standard. Some don't have a covering of glass cloth, just 3 coats or so of epoxy brushed on. The addition of cloth obviously means it has better resistance to knocks and scrapes. Damage is easily repaired, and provided it is done asap, and the substrate is dry, is perfectly acceptable. Unless you know the history of the boat it will be difficult (impossible?) to assess whether any damage has been repaired properly. The most likely areas for damage are going to be the topsides, especially the transom corners and around the bow, due to scrapes from anchors and tenders. Also the base of the keel(s) if it has taken the ground (especially in a boatyard with a rough concrete surface). I'm not sure whether moisture meters are any good on epoxy/ply constructions - unless it is the conventional timber moisture meter and the prongs pierce the epoxy coating (entailing a repair job afterwards).

 

[lw395]

No harm in asking a broker what insurance companies think of these things. Just tell them you're thinking of buying it and ask for a quote. Much better than me telling you what I think an underwriter might think. Perhaps best to go to an outfit that does its own underwriting?
Ask them at what intervals they would require surveys, so say at 20yrs old for GRP, or every five years etc. Don't know if that might be different for cedar strip.
I think Robbins in Bristol sell cedar strip, they might be worth a phone call too.
Noble insurance have a website with a database of repairers, might be a way to find a cedar strip expert.
Hope that helps.

 

[gavin_lacey]

The term wood epoxy covers quite a wide spectrum of techniques. From plywood covered with epoxy, through strip plank sheathed with epoxy/glass cloth, to multiple diagonal veneers sheathed with cloth inside and out. Along with combinations of the last two. If well built this method can be both light and strong only beaten by carbon based exotics. badly done it can be a nightmare with saturated cores that eventually turn to mush. Not all insurace companies will cover homebuilt boats but many will given a good survey. For your own peace of mind you would want a survey done by someone with plenty of experience of modern wood construction, many are clueless.

 

[DOCHO]

Ok,
thank you all for these informative reply's.
If anybody has anything more to add please do not hesitate.

 

[snowleopard]

[ QUOTE ]
Are there other coring materials than cedar strip or western red cedar. (Probably not balsa for wood/epoxy construction.)

[/ QUOTE ]

Yes. STS Tenacious was built of Siberian Larch using the epoxy strip planking method (3 layers). Not a common method but she should be good for 40 years.

 

[Seanick]

There was an article in Wooden Boat Magazine a few years ago. They spoke to several yards about cost of running three types of boats. They totted up costs over ten years of maintaining trad plank on frame, epoxy sheathed/ two pack finished timber, and GRP. It was a long and detailed article.

Epoxy sheathed came out the cheapest.

 

[simonfraser]

if it's build well, mine is waterproof ply and soaked in epoxy, it will last an age.

easy to repair and re-epoxy. nice to the touch too.

go and see an 'old' one and you'll be convinced.

 

[oldsaltoz]

G'day DOCHO,

Timber epoxy has been in use for many many years, most of the mine sweepers in WW2 were ply and epoxy, some ore still afloat today.

Your first check should be. Is the area below the waterline solid glass or is it a composite.

If the answer is not solid glass, walk away, it may save you a lot of time and money.

The reason behind this is that 'some' were built with foam types that can not get wet without falling apart, others have timber that was never properly sealed or treated.

If the area below the waterline is solid glass, it will be strong and need little or no maintenance, yet remain simple to repair.

I hope this helps.

Avagoodweekend......

 

[DownWest]

Oldsalt, I think you are talking about cored grp construction, rather than wood/epoxy. In the former, as you say, core below the waterline is a no no as a structural system (Etaps do not use it for structure)
Second the post to buy the West book. Big boats are built to the strip/glass system, but strip/cold mould veneers/ glass is better. Covey Island do some really nice stuff. Amateur built can be a disaster, but also many are very well built as amateurs can spend more time than pros. Needs a servey.
A

 

[whipper_snapper]

My Wharram cat was built in ply epoxy. This was new to me and asked around before going for it but was assured that properly made it as durable as conventional GRP.

Having worked on it a lot over the last few months I feel I know the system well. I am convinced it can be a superbly durable, light, strong system provided it is properly built by someone who understands the issues and provided that any work on it is done to high standards. You can get away with a lot on GRP, steel or wood that you cannot on ply-epoxy.

For example, the previous owner (not the builder) had drilled loads of holes in the hulls, well above the water line, and all of them were surrounded by areas of rot. Some in the deck leaked right through. Fixing has been easy but time consuming. Each bit of rot has been cut back and new ply-epoxy let in. The rot never extended far beyond the hole that caused it and I always met very dry very sound wood after just a few inches.

I only know this boat in this material, but I must assume that this is feature of the construction method. I believe the boat was very well built using good marine ply properly soaked and assembled. I am developing paranoia about sealing any and every hole that might ever see rain or sea water.

I am told this is the definitive book on the subject, although I have not managed to get my hands on a copy yet.

 

[Tranona]

You really need to find out just how it was constructed. As others have said wood/epoxy covers a range of techniques, varying from strip plank and glass composites with bonded in stiffeners and bulkheads to nearly "traditional" plank on frame but epoxy fastened - with or without mechanical fastenings. If you are serious about the boat, buy yourself a copy of the Gougeon Brothers book - readily available at Christmas present price from Wessex Resins or Robbins in Bristol. This is the bible. Strip Planking by Ian Nicholson is also useful if that method is used.

The techniques are more common in custom and semi-custom building, so the choice of design is as important as the construction method. It has been popular with home builders because arguably the skill requirement is lower and the material easier to manage - smaller section timbers, use of laminating etc. However, building conditions are important in terms of temperature and humidity.

Bruce Roberts designs often offer this method as an alternative, so you need to check thta it has been built using their design scantlings and not the builder's interpretation of a design using another method.

Because there are so few about it is unlikely that you will be able to see similar boats to compare, so really important that you get as much knowledge as possible so that you can make a general assessment even before you engage a surveyor.

On the upside - if done well, the method(s) can produce brilliant boats - but done badly its not walk away, but run!

 

[DOCHO]

I just ordered a copy of "The Gougeon Brothers on Boat Construction" book. I hope it will come in this week. If it is as good as everybody says it will be worth every penny. (For me Eurocent /forums/images/graemlins/smile.gif)

 

[whipper_snapper]

[ QUOTE ]
I just ordered a copy of "The Gougeon Brothers on Boat Construction" book. I hope it will come in this week. If it is as good as everybody says it will be worth every penny. (For me Eurocent /forums/images/graemlins/smile.gif)

[/ QUOTE ]

May I ask, where did you order from, which edition and what price ?

Thanks

 

[DOCHO]

[ QUOTE ]
May I ask, where did you order from, which edition and what price ?

Thanks

[/ QUOTE ]

Sorry about that I'am Dutch /forums/images/graemlins/grin.gif and I got it in the Netherlands.
Base price is € 39,50. This excluding Shipping. It is the 5th edition.
The place I bought it form is de Bootbouwer (The Shipbuilder).